Helicopter Sikorsky HO4S-3 Serial 55-669 Register 138589 used by US Navy USN. Built 1954. Aircraft history and location Aircraft History 138589 US Navy 1954-03-04Sikorsky S-55 c/n 55-669, ff:? del USN as HO4S-3, 138589, 04Mar54. Send Updates Use APP to upload photo @ (optional) When Now? / / Send